The present invention concerns a setting mechanism for a watch comprising a sliding crown wheel on a stem.
In a known mechanism of this type, a setting stem is movable with a translatory movement and actuates the crown wheel, which is mounted slideably on the stem, by means of levers such as a pull-out piece and a return bar. The sliding crown wheel can assume at least two positions, namely a neutral position and an active position in which it provides for transmission of the rotary movement of the stem to the gear train, for setting the watch to time. For that purpose, the sliding crown wheel is internally provided with a bore having flats, which is co-operable with flats provided on the stem. The crown teeth on its inner face engage with the gear train of the watch by way of an intermediate wheel which has to engage on the one hand with the teeth of the sliding crown wheel, which are of a particular cut, and on the other hand, with a wheel of the going train or motion work which is of normal cut. This results in a delicate compromise in regard to the cut of the intermediate wheel and irregular operation of the gear train when setting the watch to time.
Setting mechanisms are known which avoid this problem in that the crown wheel does not engage the intermediate wheel itself but clutches into engagement with a castle wheel in mesh with the intermediate wheel. Such known mechanisms are relatively complex.